They are owned by Twitter. It's basically a spyware approach - Twitter wants to be able to track users across apps, but there are no cookies or tracking pixels in the mobile app ecosystem.

Instead, they get developers to bundle this SDK into their apps, which subsequently reports back to Twitter, enabling Twitter to track users across the app ecosystem.

I think you're correct to be concerned about how they make money, because the answer is unfortunately by spying on your users.

Re: enterprise version -- after joining forces with Twitter[1] they opened the enterprise version up[2]

[1] http://www.crashlytics.com/blog/crashlytics-is-joining-force... [2] http://www.crashlytics.com/blog/crashlytics-enterprise-is-no...

The rumour circulating around is that they have the ability to detect which other applications are running or installed on a mobile device. Certainly for applications that have this service installed, they could correlate the owner of the device to an ID. That might help with targeting ads, but it's just a theory.

Well, it's a bit similar to Google Analytics in that sense. I suppose they gain 'insight'.

I think realistically Twitter needed a good crash reporting service for their own applications. They didn't want to build it themselves, so they bought Crashlytics. They get the best crash reporting utility completely tailored to their needs and keeping the service up and running for others is just an added benefit. Maybe they'll be able to monetize it down the road, but for now they get crash reporting on the cheap.

Data on your users.